Benefits of Floor Heating Control Individual Room Temperature Control In Hydronic Floor Heating Applications – Simulation Studies, August 2003 Danfoss Floor Heating Hydronics

2 Benefits of Floor Heating Control Personal Thermal Comfort Room temperature is a main factor for personal thermal comfort The desired room temperature depends on activity, clothing, and personal ”taste” Desired temperatures varies for each room in the house Kitchen ~ 20 C° Bedroom ~ 17 C° Bathroom ~ 23 C° Living room ~ 20 C°

3 Benefits of Floor Heating Control How Do We Achieve Optimal Personal Thermal Comfort ? In order to achieve the desired temperature in each room it must be possible for the user to define/set the temperature in each room It must be possible to differentiate temperatures between the rooms, - e.g. typically the user wishes the bathroom to be warmer than the bedroom The heating system should at all times supply the correct amount of energy needed to each room so that large fluctuations resulting in the room being too warm or too cold is avoided Optimal comfort is achieved when the user has exactly the temperature desired in each room of the house

4 Benefits of Floor Heating Control Individual Room Temperature Control Desired temperature in bathroom Desired temperature in living room Desired temperature in bedroom Temperature without individual room control Temperature with individual room control Hour °C temperature

5 Benefits of Floor Heating Control Individual Room Temperature Control – Conclusion In order to fulfill the desire for optimal personal thermal comfort it is necessary to utilize Individual Room Temperature Controls of your heating system

6 Benefits of Floor Heating Control Individual Room Temperature Controls Precise regulation of the temperature corresponding to the specific set-point chosen for each room by the user Individual Room Temperature Controls adjust heat flow depending on user pattern, free heat through windows, appliances, etc.  Optimal personal thermal comfort Individual Room Temperature Controls adapt heat output to heat loss in each room  Minimized costs with regard to energy consumption/saving

7 Benefits of Floor Heating Control The Simulation Studies Danfoss has carried out simulation studies in order to clarify the importance of Individual Room Temperature Control of the heating system with regard to: Personal thermal comfort Energy consumption

8 Benefits of Floor Heating Control The Simulation System: IDA Indoor Climate and Energy 3.0 IDA Indoor Climate and Energy 3.0 is a general-purpose modeling and simulation tool for modular systems where components are described with equations IDA Indoor Climate and Energy 3.0 is a new generation tool for simulation of thermal comfort, indoor air quality and energy consumption in buildings More than 900 registered users, mostly HVAC designers but also educators and researchers First version was released in May Version 3.0, released in November 2001, marks a major development step with several significant improvements

9 Benefits of Floor Heating Control The Simulation System: IDA Indoor Climate and Energy 3.0 IDA Indoor Climate and Energy 3.0 is developed by the company EQUA in close co- operation with a network of academic institutions, each contributing through expert usage and model development: Royal Institute of Technology, Stockholm, Sweden Building Services Engineering, Sweden Helsinki University of Technology, Heating, Ventilating and Air-Conditioning, Finland Hochschüle für Technik+Architektur, HLK Engineering, Luzern, Switzerland University of Kassel, Department of Building Physics, Germany Norweigan University of Science and Technology, Dept. of Refrigeration and Airconditioning, Norway For more information please refer to the EQUA homepage

10 Benefits of Floor Heating Control System Control Methods Automatic control of flow temperature using an electronic weather compensator With individual room temperature control Without individual room temperature control Manual control of flow temperature by occupant operation of self-acting flow regulator With individual room temperature control Without individual room temperature control

11 Benefits of Floor Heating Control Automatic Control of Flow Temperature Using an Electronic Weather Compensator No occupant interaction on the heating system during heating season Apartment with 6 rooms No reference room control Doors to bathroom and bedroom closed and the other doors open Flow control to each room is on/off with a dead-band of 0.25 °C Minimum operative temperatures registered in the rooms equals desired temperatures Flow temperature is adjusted to ensure desired indoor temperatures at a coldest day of -12°C Thermal comfort related to tube layout is not included in the study Only energy consumption in association with room heating is considered - efficiency of the energy producing and delivering system is not considered

12 Benefits of Floor Heating Control Manual Control of Flow Temperature by Operation of Self-acting Flow Regulator The occupant checks the flow temperature with regular intervals and change the set-point of the flow temperature regulator if the deviation between proposed value and present value of the flow temperature is more than 2°C No occupant interaction on the room thermostats during heating season Apartment with 6 rooms Doors to bathroom and bedroom closed and the other doors open Flow control to each room is on/off with a dead-band of 0.25 °C Minimum operative temperatures registered in the rooms equals desired temperature Flow temperature is adjusted to ensure desired in-door temperatures at a coldest day of -12 °C Thermal comfort related to tube layout is not included in the study Only energy consumption in association with room heating is considered - efficiency of the delivering and energy producing system is not considered

13 Benefits of Floor Heating Control Settings For Both Simulations Heating season: 9 months (September to May) Set-point temperatures (degrees Celsius) Living room20°C Corridor20°C Bedroom17°C Bathroom23°C Kitchen20°C Childrens room20°C Measured results % of time during heating season, where operative temperature deviates with less than 1 celcius degree from set-point temperature

14 Benefits of Floor Heating Control Automatic Control Of Flow Temperature Using An Electronic Weather Compensator Without individual room temperature control With individual room temperature control % of time during heating season, where operative temperature deviates with less than 1 celcius degree from set-point temperature

15 Benefits of Floor Heating Control Manual Control of Flow Temperature by Operation of Self-acting Flow Regulator Without individual room temperature control With individual room temperature control % of time during heating season, where operative temperature deviates with less than 1 celcius degree from set-point temperature

16 Benefits of Floor Heating Control Conclusions: Personal Thermal Comfort Significantly improved personal thermal comfort with individual room temperature controls Individual Room Temperature Control is optimal in combination with both electronic weather compensator and occupant interaction for regulation of flow temperature

17 Benefits of Floor Heating Control Results on Energy Consumption Flow temperature control Pre-setting of manifold valves Without room temperature controls With room temperature controls Reduction in energy consumptio n Automatic – using an electronic weather compensatorYes8372 kWh7392 kWh12% Automatic – using an electronic weather compensatorNo9550 kWh7390 kWh 23% Manual – occupant operation of self-acting flow regulator Yes9009 kWh7552 kWh16% Manual – occupant operation of self-acting flow regulator No10412 kWh7681 kWh 26%

18 Benefits of Floor Heating Control Conclusions: Energy Consumption Significant energy savings can be achieved with Individual Room Temperature Controls  15-25% Significant energy savings can be achieved in combination with both electronic weather compensator and occupant interaction for regulation of flow temperature The simulation results support independent research by e.g. M. Bauer, University of Stuttgart, who shows possible energy savings of approx % for similar applications

19 Benefits of Floor Heating Control Simulation Data: Automatic Control Of Flow Temperature Using An Electronic Weather Compensator Heating season: 9 months (September to May) Set-point temperatur e ( o C) % of time during heating season, where operative temperature deviates with less than 1 o C from set-point temperature Without room control With room control Living room2070%98% Corridor209%100% Bedroom170%67% Bathroom2346%91% Kitchen202%99% Childrens room200%97%

20 Benefits of Floor Heating Control Simulation Data: Manual Control of Flow Temperature by Operation of Self-acting Flow Regulator Heating season: 9 months (September to May) Set-point temperatur e ( o C) % of time during heating season, where operative temperature deviates with less than 1 o C from set-point temperature Without room control With room control Living room2030%96% Corridor209%97% Bedroom170%56% Bathroom2330%98% Kitchen207%92% Childrens room202%88%